*Note: To protect their privacy, only the first names of family members in this story have been used.

GROZNY, Chechnya, 3 March -- The number 907 is the only link, the only piece of evidence Zara has to her missing 31-year-old son Ruslan.

It was February 2003 in the Chechen village of Pervomayskaya. He was headed to a neighbor's house to watch a boxing match on television.

Zara with a picture of her missing son

That same night, she says, Russian security forces surrounded the house and took away her son. She has not seen or heard from him since.

"The neighbor says the men were wearing Russian camouflage and arrived in Russian tanks and trucks," says Zara. "Only one, probably a Chechen, was wearing a ski mask." She says she remembers seeing a number on the license plate of one of the Russian trucks: 907.

Since that time, Zara says she has written hundreds of letters mentioning the number 907 to everyone from Russian President

Vladimir Putin to members of the Duma (Russian Parliament) — anyone that might be able to help her get her son back.

"He wasn't involved with the militants," she says. "He was very good. He just didn't have his passport with him because he was only going to the neighbor's."

Russian human rights organization, Memorial, monitors kidnappings and abuse in the Northern Caucasus. Memorial says it has evidence that Russian forces and Chechen security forces allied to Russia have been involved in 3,000 kidnappings since 1999.

It's ironic, they say, because one of the stated Russian goals of launching the second Chechen War in 1999 was to stop the rampant kidnapping of foreign journalists, aid workers and politicians.

Memorial has begun building a database of those they believe have disappeared at the hands of security forces, including details of the abduction and background information on the individuals. So far they've compiled information on more than 1,700 cases.

"We don't want them to be forgotten," says Katarina Sokirianskaia, a case worker for Memorial.

In the efforts to capture and kill separatists, Sokirianskaia says, security forces are actually helping to drive people into their camps.

"You can see how a young man whose two brothers have disappeared, and he himself has been detained and beaten, might be more inclined to join the militants or a separatist movement," she says.

But Sokirianskaia concedes that terrorism is a very real problem in the Northern Caucasus. Just one example is the 2004 Beslan school siege, in which militants linked to Islamic terror leader Shamil Basayev took over 1,000 students, teachers and parents hostage. Over 300 people died — half of them children.

Critics say a bungled rescue attempt by Russian and local security forces added to the body count when a gymnasium roof caught fire and collapsed. Many hostages were also killed in the crossfire.

The question then becomes: How do you respond firmly to these events while maintaining basic human rights? Officials need to broaden their strategic vision, Sokirianskaia says.

"The federal government has systematically killed all the moderate separatist leaders," she says. "All that's left is the radical Islamists like Basayev, which is exactly what they wanted. When you combat terrorism, maybe you should also fight corruption. For instance, how did the terrorists get into Beslan school? When I go through a checkpoint my documents are being checked, my bags are being checked."

Sotsita with a photo of her missing son Razvan

Sotsita's family is an illustration of the complexity and potential cycle of violence created by security forces' tactics in the region.

She says that on May 1, 2002, Russian security forces picked up her son Razvan, along with two other friends, in downtown Grozny. One of the friends was released and said that the security forces tried to get the three of them to confess to bombing a Russian military bus.

Memorial says another tactic of security forces in Chechnya is to detain young Russian men who fit the profile of potential militants. They then hold them as handy scapegoats to use when an appropriate crime or act of terror occurs.

Sotsita says Razvan was not involved with any militant groups. But here is where it becomes more complicated: Her daughter, she says, was married to one.

"My daughter was married to a militant who was executed by security forces," she says. "But when her husband's brother was also wounded later on, he came to her for help at our home."

Sotsita says she was at work at the time, but her daughter Zarema hid the man in their attic. When she came home later that day, she says Russian and Chechen security forces surrounded the house and told them to come out.

"They began beating my two sons," she says. "They punched and kicked my son Baudin so hard they broke his jaw and broke five ribs, but he had no idea what was going on."

She says at that point Zarema began to cry.

"Stop it," Sotsita says her daughter told the security forces. "She said to them 'they don't know anything.'"

Zarema showed the security forces where the man was hiding and they killed him on the spot, claiming he had a grenade.

Sotsita says after the incident she was held for one day, but her two sons were detained and tortured for three months with electric shock and beatings, even though they knew nothing.

Zarema was also detained. Eventually Sotsita's sons were released but Zarema is still being held in a prison and Sotsita is in regular contact with her.

She still has no word on her son Razvan, abducted on May Day, four years ago.

She produces his picture and asks for help. Another son, Raymon, comes to take her home. He tells us how Chechen security forces detained him, too, when they thought he looked suspicious.

He says they used electric shock to get him to say whether he had a weapon or not.

"It feels like a knife that is inside you," he says, "driving through your body. After they used it on my leg also, I couldn't move it."

Grozny, Chechnya

"The problem of terrorism in Russia is that it's homegrown," says Sokirianskaia of Memorial, "and it's rooted ... in the protracted, unresolved conflict with Chechnya. But I believe, even with such horrible crimes, they must be combated within the framework of the law. Otherwise violence replicates violence, and that's why you have people taking schools hostage. You produce terror by kidnapping people and torturing people."

For Zara, the outlook is bleak. She says two of her other sons were killed in the Russian bombing of Grozny in 1999. Now with her son Ruslan missing, all she has is one son.

But she says he is so rattled by the war and the loss of his brothers that he's unable to work. Both she and her husband are in failing health. The return of Ruslan is the only thing she feels might improve their dire circumstances. So far, the search for the Russian truck with plate number 907 has led nowhere.

When asked if she thinks Ruslan is still alive, she begins to cry.

"I hope so."